1. Field of the Invention
The present invention relates to an air-sealed body and a method for manufacturing the same, in particular, to an air-sealed body capable of automatically opening an air valve and a method for manufacturing the same.
2. Related Art
An air-sealed body made of a resin film is heat-sealed into a sealed state to form an air column, and provided with an air-filling port for filling air. After air is filled in the air column via the air-filling port, the air-sealed body can be used as a cushioning material in inner packaging.
A conventional air-sealed body is disclosed in Japanese Utility Model Application Laid Open No. 5-95851 entitled “SEALED BAG FOR FLUID”. In this utility model, each air column is disposed with a check valve independent of one another, and an inflow port on the top of each check valve is aligned with a heat-sealing line and joined thereto. After air flows into an air passage, the air passage expands to open the check valves, so as to fill the air into the air columns. However, in such a structure, each air column is filled separately as the check valve is independent of one another, and thus it is impossible to fill air into multiple air columns at the same time. Moreover, the manufacturing process is quite complicated, in which each check valve has to be placed at a predetermined position in the air column one by one and then joined thereto through heat-sealing. Once the placing position of the check valve or the joining position of a heat-sealing mold offsets, the check valve may not be fixed in the air column, or the inflow port on the top of the check valve exceeds the heat-sealing line of the heat-sealing mold for joining, which may stop the check valve from being opened with the expansion of the air passage after air is filled in to cause an inflation, thereby preventing the air from entering the air column.
Another air-sealed body is disclosed in Taiwan Patent No. 00587049. In this patent, whether air is allowed to enter a sealed body or not is controlled through a passage of an open/close valve formed by joining two inner films to an outer film on one side. After air is filled in, the sealed body expands to block the passage. This open/close valve described herein only functions to block the air in the sealed body from leaking. However, when the air passage expands after air is filled in, even if the two outer films are pulled open outward under the thrust of the air, the open/close valve may not be pulled open outward with the motion of the two outer films, and the two inner films of the open/close valve still attach to each other so that the air passage inlet cannot be opened. According to this design, air cannot be automatically filled in the sealed body.
Therefore, it is a technical problem to be solved by the inventor of the present invention and those engaged in the related art to design a sealed body, which is capable of automatically opening its air inlet to fill in air continuously so as to save the air-filling time, and also capable of automatically closing the air when air is filled in and automatically locking the air after the air closure, thus preventing the air from leaking for a long time and simplifying the manufacturing process to improve the yield.